U.S. patent number 4,533,561 [Application Number 06/431,873] was granted by the patent office on 1985-08-06 for low-fat spread and process.
This patent grant is currently assigned to Nabisco Brands, Inc.. Invention is credited to John Ward.
United States Patent |
4,533,561 |
Ward |
August 6, 1985 |
Low-fat spread and process
Abstract
Disclosed are a low-fat spread, preferably butter flavored, and
a process for preparing it. The spread is a water-in-oil emulsion
of relatively low calorie content due to a restricted fat content
of from 30 to 70%, preferably 30 to 50%. The fat phase of the
emulsion comprises a blend of a liquid oil with a hardstock, and
the blend comprises from 10 to 30% of the fatty acids as C10, C12,
C14 and C16 fatty acids and these fatty acids are predominantly in
the trisaturated glyceride form. The hardstock is preferably a
randomly interesterified mixture of a saturated lauric acid fat and
a saturated palm fat or beef fat. The water is dispersed within the
fat to a size which will permit cooling to a degree effective to
achieve significant beta-prime crystal form. Preferably, the water
globules will be reduced to about one micron in diameter, and the
solid fat will be substantially completely in the beta-prime
form.
Inventors: |
Ward; John (Mississauga,
CA) |
Assignee: |
Nabisco Brands, Inc.
(Parsippany, NJ)
|
Family
ID: |
23713814 |
Appl.
No.: |
06/431,873 |
Filed: |
September 30, 1982 |
Current U.S.
Class: |
426/603;
426/604 |
Current CPC
Class: |
A23D
7/015 (20130101) |
Current International
Class: |
A23D
7/015 (20060101); A23D 003/00 (); A23D
003/02 () |
Field of
Search: |
;426/603,604,607 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Yoncoskie; Robert
Attorney, Agent or Firm: Kornutik; Richard
Claims
I claim:
1. A low-fat spread comprising: from about 50% to about 70% of a
highly-dispersed aqueous phase; and from about 30% to about 50% of
a continuous fat phase comprising a blend of from about 70% to
about 95% by weight of a liquid vegetable oil and from about 5% to
about 30% of a hardstock, the blend comprising from 10 to 30% of
the fatty acids as C10, C12, C14 and C16 fatty acids, these fatty
acids being predominantly in the trisaturated glyceride form, and
the solid fat is present predominantly in the beta-prime crystal
form.
2. A low-fat spread according to claim 1 wherein the hardstock has
an SFI solids content of at least 30% at 92.degree. F., and said
hardstock comprises a randomly interesterified mixture of a
saturated lauric acid fat and a second saturated edible oil,
wherein the lauric acid fat and the second oil are present in the
weight proportions of from about 90:10 to about 40:60.
3. A low-fat spread according to claim 2 wherein the lauric acid
fat comprises a member selected from the group consisting of
coconut oil, babassu nut oil, palm kernel oil, palm kernel oline, a
fractionated lauric oil having fatty acid components equivalent to
coconut oil, babassu nut oil, palm kernel oil or palm kernel oline,
and combinations thereof.
4. A low-fat spread according to claim 2 wherein said second oil
comprises palm oil or tallow.
5. A freeze/thaw stable low-fat spread according to either of
claims 1 or 2 wherein the aqueous phase is dispersed into globules
of about 1 micron in diameter.
6. A freeze/thaw stable low-fat spread according to either of
claims 1 or 2 wherein the solidified fat is substantially
completely in the beta-prime form.
7. A low-fat spread according to claim 1 wherein the distribution
of fatty acids in the fat phase is substantially as follows:
8. A low-fat spread according to any of claims 1, 2 or 7 wherein
the aqueous phase is dispersed into globules of about 1 micron in
diameter and the solidified fat is substantially completely in the
beta-prime form.
9. A freeze/thaw stable low-fat spread having a ratio of
polyunsaturated fatty acids to saturated fatty acids of greater
than 1.5, which comprises: from about 50 to about 70% of a highly
dispersed aqueous phase having globules of about one micron in
diameter; and from about 30% to about 50% of a continuous fat phase
comprising a blend of from about 70% to about 95% by weight of a
liquid vegetable oil and from about 5% to about 30% of a hardstock
comprising a blend of a liquid oil with a hardstock, the blend
comprising from 10 to 30% of the fatty acids as C10, C12, C14 and
C16 fatty acids, these fatty acids being predominantly in the
trisaturated glyceride form, and the solid fat is present
predominantly in the beta-prime crystal form.
10. A low-fat spread according to claim 9 which has a ratio of
polyunsaturated to saturated fatty acids of greater than 2.
11. A low-fat spread according to claim 9 which has a trans isomer
content of less than 1%.
12. A low-fat spread according to claim 9 wherein the hardstock has
an SFI solids content of at least 30% at 92.degree. F., and
comprises a randomly interesterified mixture of a saturated lauric
acid fat and a second saturated edible oil, the mixture comprising
said lauric acid fat and said second oil in the weight proportions
of from about 80:20 to about 40:60.
13. A low-fat spread according to claim 12 wherein the distribution
of fatty acids in the fat phase is substantially as follows:
14. A process for preparing a low-fat spread comprising: finely
dispersing from about 30% to about 70% of an aqueous liquid within
from about 30% to about 70% of a continuous fat phase comprising
from about 70% to about 95% by weight of a liquid vegetable oil and
from about 5% to about 30% of a hardstock, the combined oil and
hardstock comprising from 10 to 30% of the fatty acids as C10, C12,
C14 and C16 fatty acids, and these fatty acids being predominantly
in the trisaturated glyceride form; finely dispersing the aqueous
phase within the oil phase sufficiently to achieve a water-in-oil
emulsion sufficiently stable to permit cooling under conditions
effective to crystallize the hardstock in predominantly the
beta-prime form without breaking the emulsion; and cooling the
emulsion in a scraped-surface heat exchanger to a final exit
temperature in the range of from about 30.degree. F. to about
55.degree. F. to crystallize the solid fat portion in predominantly
the beta-prime crystal form.
15. A process according to claim 14 wherein the aqueous phase is
uniformly dispersed to a water globule size of approximately 1
micron in diameter.
16. A process according to claim 14 wherein the hardstock has the
SFI solids content of at least 30% at 92.degree. F., and comprises
a randomly interesterified mixture of a saturated lauric acid fat
and a second saturated edible oil, the mixture comprising said
lauric acid fat and said second oil in the weight proportions of
from about 90:10 to about 40:60.
17. A process according to claim 14 wherein the fat phase comprises
from about 30% to about 50% and the aqueous phase comprises from
about 50% to about 70%, both percentages based on the weight of the
emulsion.
18. A process according to claim 14 wherein the fatty acid
distribution within the oil phase is as follows:
19. A process according to claim 18 wherein the aqueous phase is
uniformly dispersed to a water globule size of approximately 1
micron in diameter.
20. A process according to claim 19 wherein the water-in-oil
emulsion is prepared by passing an admixture of the aqueous and fat
phases tangently into a chamber under conditions effective to cause
them to move spirally toward a centrally-located exit path from the
chamber while creating shear within the admixture sufficient to
finely disperse the aqueous phase within the fat phase.
21. A process according to claim 20 wherein the water-in-oil
emulsion comprises from about 30% to about 50% of the fat phase and
from about 50% to about 70% of the aqueous phase.
Description
BACKGROUND OF THE INVENTION
The present invention relates to low-fat spreads; particularly, to
spreads suitable as low-calorie substitutes for butter and
margarine, and to a process for preparing them.
Low-fat spreads are recognized as those having from 30% to less
than 80% fat content. Typically, they are water-in-oil emulsions.
Low-fat spreads suitable for use as margarine substitutes are
required to have certain flow or spread characteristics and should
resist free oil or free water separation. And, they should
otherwise simulate the characteristics of butter and margarine,
including rapid melt on the tongue, good mouthfeel, fairly shiny
appearance, good stability to heat such as when spread on hot
foods, and freeze/thaw stability.
Among the most desirable low-fat spreads are those which offer a
significant fat and calorie reduction as compared to conventional
margarine or butter. Diet margarines are generally recognized as
having less than half of the normal fat content, thus less than
half the calories of normal margarine which contains about 80% fat.
Typical diet margarine products which contain 60% or more of an
aqueous phase have been the source of considerable technical
difficulty and investigation.
The art is replete with prior art attempts to provide low-fat
butter or margarine substitutes. Among these is U.S. Pat. No.
3,457,086 to Josefowicz et al, which teaches the production of a
protein-free spread which contains as low as 35% fat. The patent
states that the observance of specified conditions is necessary to
maintain the emulsion in the water-in-oil form. Unfortunately,
products of this type tend to have a watery flavor because of their
high water content and the absence of milk proteins which help
impart the desirable butter-like taste of margarine or butter, but
which cannot be tolerated in the product because of their emulsion
destabilizing effect. Moreover, the high water content tends to
make emulsions of this type rapidly break down on hot foods,
tending to make foods like toast become soggy and unappetizing.
Moreover, while some consumers have found it convenient to buy
large quantities of margarine or butter at sale prices and then
freeze them, low-fat spreads prepared by that and similar processes
cannot tolerate freezing. Upon thawing, the emulsion breaks down
with consequential release of its water phase.
Typically, low-fat spreads of the type disclosed by Josefowicz et
al, cited above and Spitzer et al in U.S. Pat. No. 3,360,377,
result in very tender emulsions when desirably low fat contents, on
the order of about 40%, are employed. For example, Spitzer et al,
which discloses examples A-J of different suitable margarine oils,
D and E being randomized coconut oil and coconut oil blends,
emphasize the need for rapid cooling after homogenization to
maintain emulsion stability, especially when lower-fat contents are
employed. Spitzer et al disclose that 20% to about 55% oleaginous
ingredients can be formed into an emulsion suitable for a margarine
substitute when certain procedural constraints are observed. For
example, in forming the emulsion, it is necessary to first form a
coarse emulsion at a temperature within the range of around
80.degree. to 140.degree. F. and then cool prior to forming a fine
emulsion in a colloid mill at a temperature within the range of
around 73.degree. to 113.degree. F. The temperature at which the
chilled emulsion assumes an appropriate consistency is disclosed as
generally within the range of from around 50.degree. to 72.degree.
F., for example 59.degree. F. These emulsions will not tolerate
cooling in conventional scraped surface chilling processors at
temperatures below 50.degree. F. Processing at temperatures of
around 50.degree. F. or below results in breakdown of the emulsion.
And, at temperatures in the 50.degree. to 60.degree. F. range, the
emulsion becomes extremely stiff and heavy. The emulsions become so
stiff and heavy that they often present problems of flow into the
packaging container or physically exude free moisture from the
mass. Further, like the products produced by Josefowicz et al, the
emulsions of Spitzer et al cannot tolerate the presence of milk
protein as conventionally employed in margarines and require
elevated levels of emulsifiers, especially at low fat contents.
Further exemplary of prior art low-fat margarine processing is U.S.
Pat. No. 3,889,005 to Brammer et al. According to that disclosure,
an emulsifier system consisting essentially of saturated fatty acid
partial glycerides and unsaturated fatty acid partial glycerides is
said to improve emulsion stability. However, evidence that low
temperature working in a scraped-surface chilling process cannot be
achieved is the statement in the examples that the product is
worked and packed at 20.degree. C. (68.degree. F.). At these
temperatures, the crystal form of the solid fat will be
predominantly in the beta form which results in large crystals, on
the order of 25 to 50 microns. Apparently, these large crystals of
fat and the high content of water in globules of 3-5 microns,
together create a stiffness at low temperatures in the chilled
processor which ruptures the fat boundaries separating the water
globules and causes emulsion breakdown. This is typical of known
low-fat margarines based on water-in-oil emulsions.
A further deficiency of many diet margarine products is that they
cannot retain emulsion stability when subjected to freezing
temperatures and then thawed. Typically, exposure to freezing
temperatures and subsequent thawing results in coalescence of water
droplets due to the expansion of the dispersed water during ice
crystal formation and subsequent contraction upon thawing. The
problem is especially acute in diet margarines because the water
usually predominates over the fat in concentration, leaving the fat
highly stretched out and incapable of maintaining the water in
dispersed form as it stretches and then contracts during the
freeze/thaw cycle. Some diet margarines have overcome this
deficiency in freeze/thaw performance by the addition of gelatins
and gums to the dispersed water phase. Such diet margarines still,
however, require scraped-surface cooling at temperatures higher
than 50.degree. F., have poor stability at elevated temperatures,
and have an undesirable mouthfeel.
In an effort to overcome the problems caused by the presence of
protein and low fat content in low-fat spreads, Bodor et al
disclose in U.S. Pat. No. 4,103,037 the use of a gelling agent,
such as gelatin, having a melting point sufficiently high to
withstand room temperature yet low enough to allow it to melt in
the mouth. This gelling agent ties up all available water into
minute, solid particles which are dispersed throughout a continuous
fat phase. These multiple particles contain the water soluble
flavors and salt, and diminish the flavor impact of these
components.
In further evidence of the poor stability of the currently
available low-fat spreads based upon water-in-oil emulsions, are
several more recent patents which employ oil-in-water emulsions.
Among these are U.S. Pat. No. 4,238,520 to Miller et al, which
discloses an oil-in-water emulsion having stably dispersed therein
about 20% to 40% fat and preferably employs from about 2% to 5% of
a lipoidal emulsifier and 0.5% to 3.25% of a thickening agent. In
another approach, Bosco et al, U.S. Pat. No. 4,279,941 disclose a
spread based upon an oil-in-water emulsion containing from 5% to
40% fat and employing hydrophilic emulsifiers in combination with
stabilizing agents and fats having specified SFI profiles. While
products of the types described in these patents do have advantages
in terms of emulsion stability and the ability to employ protein,
they are a departure from more typical margarine technology based
upon water-in-oil emulsions, and thus require significantly
different processing.
There remains a need for a water-in-oil based low-fat spread which
has improved stability and provides an effective substitute for
conventional margarine and butter under a broader range of
conditions of storage and use.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved
low-fat spread and a process for preparing it.
It is a more specific object of the present invention to provide an
improved low-fat, preferably butter-flavored, spread and a process
for preparing it, wherein the product is based upon a water-in-oil
emulsion which provides an effective substitute for butter and
conventional margarine under a broad range of conditions of storage
and use.
It is another specific object of the invention to provide an
improved low-fat, preferably butter-flavored, spread and a process
for preparing it wherein the product is based upon a water-in-oil
emulsion and can include dairy proteins to enhance the flavor and
nutrition of the product without adversely affecting emulsion
stability.
It is a further more specific object of the present invention to
provide a low-fat, preferably butter-flavored, spread and a process
for preparing it, wherein the spread has a consistency in
rheological properties which enables it to remain suitably firm at
room temperature, but yet not unduly hard at refrigerator
temperatures.
It is yet a further specific object of the invention to provide a
low-fat, preferably butter-flavored, spread based upon a
water-in-oil emulsion and a process for preparing it, wherein the
product remains solid and easily spreadable at all temperatures
within the range of from 32.degree. F. to about 80.degree. F., yet
melts down quickly in the mouth to release flavor without imparting
a "waxy" mouthfeel and remains as a stable emulsion at temperatures
typically encountered for hot food dishes.
It is yet a further specific object of the invention to provide a
low-fat, preferably butter-flavored, spread based upon a
water-in-oil emulsion and a process for preparing it, wherein the
emulsion remains stable during freeze/thaw cycling.
It is another object of the present invention to provide a
low-calorie, preferably butter-flavored, spread based upon a
water-in-oil emulsion and a process for preparing it, wherein the
spread is low in trans isomer content.
It is another object of the present invention to provide a
low-calorie, preferably butter-flavored, spread based upon a
water-in-oil emulsion and a process for preparing it, wherein the
spread has a high ratio of polyunsaturated to saturated fatty
acids, preferably greater than 1.5 for stick-type products and
greater than 2.0 for soft or tub-type products.
It is another object of the present invention to provide a low-fat,
preferably butter-flavored, spread based upon a water-in-oil
emulsion and a process for preparing it, wherein the spread has a
desirable surface sheen.
It is another object of the present invention to provide a process
for preparing a low-fat spread based upon a water in oil spread
which enables low-temperature working after emulsification to
achieve a desirable polymorphic crystalline behavior which results
in improved rheological properties.
It is another specific object of the present invention to provide a
low-fat, preferably butter-flavored, spread and a process for
preparing it, wherein the spread is based upon a water-in-oil
emulsion and provides a close simulation to the desirable
attributes and characteristics of butter and margarine while
presenting a caloric content significantly reduced therefrom.
These and other objects are achieved according to at least the
preferred embodiments of the present invention which provides an
improved low-fat spread and a process for preparing it. The spread,
in its broad aspects, comprises: from about 30 to about 70% of a
highly-dispersed aqueous phase; and from about 30% to about 70% of
a continuous fat phase comprising a blend of from about 70% to
about 95% by weight of a liquid vegetable oil and from about 5% to
about 30% of a hardstock, the blend comprising from 10 to 30% of
the fatty acids as C10, C12, C14 and C16 fatty acids and these
fatty acids are predominantly in the trisaturated glyceride form,
the solid fat being present predominantly in the beta-prime crystal
form. The hardstock preferably has an SFI solids content of at
least 30% at 92.degree. F., being a randomly interesterified
mixture of a saturated lauric acid fat and a second saturated
edible oil, the mixture comprising said lauric acid fat and said
second oil in the weight proportions of from about 90:10 to about
40:60. Preferably, the aqueous phase will be finely dispersed into
globules of about one micron or less in diameter and the solid fat
will be substantially completely in the beta-prime form.
The process according to the invention in its broad aspects
comprises forming a liquid emulsion according to the above
formulation, finely dispersing the aqueous phase within the fat
phase to achieve a water-in-oil emulsion sufficiently stable to
permit cooling under conditions effective to crystallize the
hardstock in predominantly the beta-prime crystal form without
breaking the emulsion; and cooling the emulsion under conditions
effective to crystallize the solids content in predominantly the
beta-prime crystal form. Preferably, the aqueous phase is uniformly
dispersed to a water globule size of approximately one micron in
diameter. This enables cooling the emulsion in conventional
scraped-surface heat exchangers at temperatures of from 30.degree.
F. to about 55.degree. F. to achieve predominantly beta-prime
crystalline fat formation. Most preferably, the exit temperature
will be below 50.degree. F. Preferably, the dispersion of the
aqueous phase and the subsequent cooling and crystallization are
conducted under conditions effective to produce substantially all
crystals in the beta-prime form.
BRIEF DESCRIPTION OF THE DRAWING
The invention will be better understood and its advantages will be
more apparent when the following detailed description is read in
light of the accompanying drawing wherein:
The FIGURE is a graph showing the results of a comparison of the
penetration readings for a product produced according to Example 1
to four current commercial diet margarines.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, it is now possible to formulate a diet
margarine comprising vegetable oils, having surprisingly good
rheological properties which include freeze/thaw stability,
negligible oils off at 80.degree. F., a brighter gloss due to the
extra light which is reflected from the finer crystals of the
beta-prime state, and a surprisingly good consistency of
penetration values within the range of from 25.degree. to
75.degree. F.
While not wishing to be bound to any particular theory, evidence
indicates that these properties may be attributed to the use of a
defined type of hardstock with liquid vegetable oils and the fine
dispersion of the aqueous phase which enable the achievement of a
unique polymorphic behavior in the fat phase. The properties of the
emulsion enable cooling at temperatures as low as 30.degree. F. to
permit the solidifying portion of the fat to crystallize in the
beta-prime form. It is believed that these crystals, typically
needle-shaped crystals of not more than one micron in length and
much smaller than the beta crystals obtained at temperatures above
50.degree. F., more typical of low-fat spread processing, are
permitted to slide past one another and past the finely dispersed
water globules during cooling. Thus, it is believed that by
maintaining particles of the fat in the beta-prime form and the
size of the water globules in a similarly small size, the particles
of fat and water can move freely within a continuous liquid oil
phase. The discontinuous solid fat and water portions remain of
such a small size during cooling and working that a consistency in
rheological properties is achieved which essentially eliminates any
tendency to break the emulsion as happens during the
low-temperature processing of conventional low-fat emulsions in
scraped surface cooling equipment such as Votator heat exchangers
of the "A" type.
The particular composition of the continuous oil phase is also
believed to contribute an unusually strong interfacial film which
allows high shearing of the dispersed water phase in the emulsion
preparation. This results in extremely fine and uniform water
globule size which, due to the strong interfacial film of the
continuous oil phase, does not allow coalescence of the water
droplets.
The present invention is directed to the production of low-calorie,
low-fat spreads from 70% to 30% fat content, for both tub and stick
margarine, having superior rheological properties such that they
have penetration values within the accepted ranges for normal (80%
fat) margarine product, while remaining spreadable though frozen
and possessing considerable body with minimal oil off at 80.degree.
F. All percentages in this description are based on the weight of
the subject component and weight of the total composition or a
specifically-identified portion thereof, unless otherwise
indicated.
Margarines are normally sold in two principal types, namely print,
hard or stick, margarine and soft or tub margarine. Hard or stick
margarine would have a firmness consistent with a penetration range
of 65 to 123 being in units of 0.1 mm using an ASTM grease cone at
45.degree. C. according to the official method of the American Oil
Chemists' Society (AOCS), designated Cc 16-60. Soft or tub
margarine, on the other hand, would have a firmness consistent with
a penetration range of 130 to 210.
The term "fat" as used herein is intended to include all edible,
fatty acid triglycerides regardless of origin or whether they are
solid or liquid at room temperature. Thus, the term "fat" includes
normally liquid and normally solid vegetable and animal fats and
oils. Where the term "oil" is employed herein, it is intended to
refer to those fats which are normally liquid in their unmodified
state.
It is preferred that sufficient liquid oil of sufficiently high
polyunsaturate content be employed to provide a ratio of
polyunsaturated fatty acids to saturated fatty acids in the product
of at least 1.5 in the case of stick-type products and at least 2.0
in the case of soft or tub-type products. The polyunsaturated fatty
acids are defined as cis, cis-methylene-interrupted polyunsaturated
fatty acids determined according to the Canadian Food and Drug
Directorate Method FA-59 and confirmed by gas-liquid
chromotography. Accordingly, the fat phase will comprise a blend of
liquid oil and hardstock, with the liquid oil comprising from 70 to
95% of the phase, preferably from 75 to 90%. In the case of soft
spreads, the liquid oil content will be at least 80%, permitting
the higher ratio of polyunsaturates to saturates.
A wide variety of edible liquid vegetable oils may be used in
formulating the edible fat portion of the low-calorie, low-fat
spread. These include safflower oil, sunflower oil, soybean oil,
rapeseed or canola oil, peanut oil, cottonseed oil, corn oil,
linseed oil, and wheat germ oil.
The hardstock is preferably a randomly interesterified mixture of a
saturated lauric acid fat and a saturated second oil in proportions
by weight of about 90:10 to about 40:60, preferably from about
80:20 to about 50:50. Suitable saturated fats may be obtained by
hydrogenating, either in admixture or separately, or by
fractionating a suitable fat. Suitable lauric acid fats are those
selected from the group consisting of palm kernel oline, palm
kernel oil, babassu nut oil, coconut oil, fractions of other lauric
acid oils having fatty acid components similar to these, and
mixtures thereof. Of these, babassu nut oil is preferred as
described in my previous copending Canadian Patent Application Nos.
354,417 and 354,377, filed on June 19, 1980. The fat products
disclosed in these applications are substantially free of trans
isomers and are high in polyunsaturates, being highly desirable for
use in diet margarines. While it is impractical commercially to
prepare a product having absolutely no determinable trans isomer
content, the products of the invention preferably substantially
eliminates trans isomer content. Preferred products are made under
suitable controls to assure a trans isomer content of less than 1%.
It is important in this regard that hydrogenation of the lauric
acid oil and the second oil be carried out to an iodine value of
less than 2. The term "low trans isomer content" is defined as
meaning less than 1% trans isomer content. The trans isomer content
is determined by infra-red spectrophotometry according to the
official method of the American Oil Chemists' Society designated
Cd-14-61.
Typical of the second oil in the interesterified mixture are single
oils or blends or fractions of oils including palm oil, and animal
fats such as tallow. The desired low trans content cannot be
achieved when the second oil comprises unsaturated oil such as
rapeseed oil, cottonseed oil or soybean oil; however, they may be
employed with this limitation.
The random interesterification of the hardstock component from
suitable saturated fats obtained by hydrogenation, in admixture or
separately, or by fractionating a suitable fat, is effected at an
elevated temperature and under vacuum in the presence of a suitable
catalyst. Preferably, after interesterification the product will
have a solids content of not less than 30% at 92.degree. F. (as
determined by the AOCS SFI method) and preferably a Wiley Melt
Point of about 108.degree. F. to 120.degree. F. Completion of the
interesterification reaction of the lauric/palmitic mixture is
usually determined by a 10.degree. F. lowering of the melt point of
the product as compared to the mixture prior to
interesterification.
It is possible to form the hardstock by first interesterifying the
specified oils and then hydrogenating. Such a procedure is less
preferred since completion of the interesterification is less
susceptible to precise determination than in the case where the
interesterification is effected after saturation of the
materials.
The combined fat phase will preferably comprise a predominant
proportion of C10, C12, C14, C16, and C18 fatty acids such that its
crystalline-tending behavior is oriented toward the beta-prime
state. The preferred distribution of fatty acid chain lengths will
be as follows:
______________________________________ C10 .5-3% C12 2-11% C14
.5-3% C16 7-13% C18 70-90%
______________________________________
with the proportion of C10, C12, C14, C16 fatty acids being
predominantly in the trisaturated glyceride form. This permits
achievement of the beta-prime crystalline form while maintaining
solids contents which provide a desirable product texture and yet
permit cooling under beta-prime tending temperatures without
breaking the emulsion.
The fat phase will preferably have a relatively constant level of
solids at the desired temperatures of use. In addition to the above
criteria, it is therefore preferred that the product exhibit a
solid fat index (SFI) with certain ranges. The SFI relates to the
proportion of solid triglycerides in the oil as measured under
specified conditions. It is calculated from dilatometer
measurements as described in AOCS tentative method Cd 10-57. The
best stick and soft products of the invention will be made from fat
blends having the following SFI values:
______________________________________ Solids (%) Temperature Stick
Soft ______________________________________ 50.degree. F. 13-15
8-10 70.degree. F. 8-10 6-8 80.degree. F. 5-7 4-6 92.degree. F. 2-3
1.5-2.5 ______________________________________
Less preferred products would have SFI values which vary by as much
as about 2% on either side of the various values given above.
The fat blend employed according to this invention may be initially
emulsified in conventional manner. However, the emulsion can
tolerate higher levels of protein and achieves greater stability at
low emulsifier levels than typical known low-fat spreads. These
advantages are believed to be achieved in part by the use of the
fat phase described above, and in part by the physical state of the
emulsion achieved due to the improved process.
The aqueous phase is formed in conventional fashion by blending
water with such typical ingredients as salt, proteinaceous
materials such as skim milk powder, whey protein, casein, sodium
caseinate or soy protein; preservatives such as potassium sorbate,
benzoic acid, calcium disodium EDTA; hydrophilic colloids such as
alginates, xantham, carob bean, or other vegetable gums; and
flavorants such as citric acid, lactic acid, and artificial or
natural flavors.
The emulsion will contain sufficient levels of suitable emulsifiers
such as mixed fatty acid monoglycerides; mixed fatty acid
diglycerides; mixtures of fatty acid mono- and diglycerides;
lipophilic polyglycerol esters; lecithin glycerol esters, such as
glyceryl monooleate, glyceryl dioleate, glyceryl monostearate,
glyceryl distearate, glyceryl monopalmitate, and glyceryl
dipalmitate; lactylated esters such as glyceryl-lacto esters of
fatty acids; propylene glycol esters, such as propylene glycol
monopalmitate, propylene glycol monostearate, and propylene glycol
monooleate; sorbitan esters, such as sorbitan monostearate,
sorbitan trioleate, sorbitan tripalmitate, sorbitan tristearate,
and sorbitan sesquioleate; fatty acids or their soaps such as
stearic acid, palmitic acid, and oleic acid; and mixtures thereof.
There is no known criticality in the use of any particular
emulsifier. Thus, it is fully intended that other equivalent
materials can be employed with satisfactory results. The
emulsifiers will be employed separately or in combination at levels
effective to achieve and maintain a stable emulsion. Typical levels
will be in the range of from about 0.25 to about 1.5%. (Standard
composition of calorie-reduced margarines in Canada specifies a
maximum in combination of 0.5%.)
The fat and aqueous phases are mixed at a temperature of from
100.degree. to 140.degree. F. to form an emulsion. The admixture is
then subjected to high shear to form a tight emulsion with the
water globules finely dispersed within a continuous fat phase. The
globules of water are reduced to a size effective to maintain the
emulsion in stable form, without breaking, when processed under
conditions effective to crystallize the solid fat portion of the
fat phase in predominantly the beta-prime crystalline form.
Preferably, the water globules will permit substantially complete
crystallization of solid fat in the beta-prime form. Most
preferably, the water globules will be reduced to a size of one
micron or less in diameter.
Dispersion of the water into the fine globules can be achieved in
any manner suitable. The preferred apparatus, however is of the
type described in U.S. Pat. No. 4,142,806 and Canadian Pat. No.
1,038,370 wherein the loose emulsion is fed tangentially into a
chamber wherein it is caused to flow in a spiral motion, from the
inside wall toward the center, constantly creating shear within the
emulsion at all points within the chamber. Preferably a unit of
this type, referred to by its manufacturer Gaulin Corporation as a
Gaulin Hydroshear system, is used to recirculate emulsion
maintained within a holding tank. In this configuration, the
contents of the tank will preferably be recirculated about every 15
minutes. If desired, suitable colloid mills can also be employed to
achieve the tight emulsion. Typically, however, dairy homogenizers
of the type employing a plurality of stages at high pressures to
achieve mechanical shear by enforcing the admixture of fat and
aqueous phases though a narrow orifice, tend to provide
inconsistent results. The high pressures required by this equipment
to achieve the requisite small globule size for the low temperature
emulsion stability necessary to achieve beta-prime crystal
formation, tend to invert the emulsion. However, their use is not
ruled out where they can be properly regulated to achieve the
desired results.
After emulsification, the emulsion is cooled under conditions
effective to crystallize the solid fat portion of the emulsion
predominantly, and preferably substantially completely, in the
beta-prime crystalline form. This can be accomplished by the use of
scraped-surface heat exchangers, such as Votator "A" units,
sometimes referred to as scraped-surface chilling tubes, operated
at suitably low temperatures. Typically, a series of two or three
Votator "A" units will be employed to reduce the temperature of the
emulsion to within the range of from about 30.degree. to about
55.degree. F. Preferably, the emulsion is worked up to form a
stable, fluid emulsion which emerges from the chilling apparatus at
a temperature of less than 50.degree. F. The product is then caused
to flow into tub-shaped packages or to resting tubes prior to
packaging into stick or pat form.
The present invention will be illustrated further by the following
examples and by reference to FIG. 1 which is a graph showing the
penetration values plotted as a curve of penetration against
temperature. Unless otherwise indicated, all parts are by
weight.
EXAMPLE 1
This example illustrates the formation of a soft, low-calorie
spread with a fat content of 40% and suitable for tub fill
according to the invention.
Palm kernel oline and palm oil in a 70:30 proportion were
hydrogenated at 300.degree. F. using a suspension of 0.2% nickel
catalyst (26% Ni), to an iodine value of less than 2.0 to form a
saturated product of melt point 122.degree. F. The hydrogenated
material was filtered to remove the nickel and steam stripped under
vacuum to decrease the free fatty acid content below about 0.03
wt%. Under a high vacuum of 2-3 mm Hg, the mixture was heated to
250.degree. F., and 0.05% sodium methoxide catalyst added with
intense agitation for 15 minutes. A sample of product was analyzed
to confirm that interesterification was complete, as determined by
a 10.degree. F. lowering of the melt point as compared to the
mixture prior to interesterification. The temperature of the
reaction mixture was decreased to 180.degree. F. and 0.4 wt% of a
30% aqueous solution of magnesium sulphate in hot water was added
to destroy residual catalyst. The temperature was then raised to
210.degree. F. and 1% bleaching earth was added to bleach the
product. Thereafter the interesterified material was cooled and
filtered.
The hardstock product was found to have an SFI solids value of 36%
at 92.degree. F. and a Wiley Melt Point of 112.degree. F.
The hardstock described was mixed in a proportion 16:84 with liquid
sunflower oil to form the fat portion of the following formula:
______________________________________ OIL PHASE Oil blend 39.00
Lecithin 0.20 Monoglycerides 0.50 Vitamins & Color 0.009
AQUEOUS PHASE Water 57.62 Salt 2.00 Whey Powder 0.50 Potassium
Sorbate 0.07 Citric Acid 0.001 Alginate 0.10
______________________________________
The fat phase was added first to an emulsion feed tank heated to
125.degree. F. and circulated through a Gaulin Hydroshear unit. The
water phase was heated to 125.degree. F. and added to the emulsion
feed tank with circulation continuing through the Gaulin Hydroshear
unit. The material in the tank was fully circulated through the
Hydroshear unit about every 15 minutes. The emulsion was
supercooled through two Votator scraped-surface chill tubes, then
through a worker tube, and finally through a third scraped-surface
chill tube emerging at 46.+-.2.degree. F. to be filled into tubs.
The resulting soft diet margarine spread readily, did not exhibit
oil or water separation during processing or subsequently at room
temperature and had good mouth break. In addition, the product had
excellent freeze/thaw stability when cycled for 48 hour periods at
25.degree. F. and 80.degree. F.
Superior rheological properties of the resulting low-calorie spread
are evidenced by the following penetration data comparing the
product of this example to four commercially-available low-calorie
spreads. Penetrations were conducted with an ASTM grease cone
measuring units of 0.1 mm at temperatures of 25.degree. F.
representing freezer temperatures, 45.degree. F. representing
refrigeration temperatures, and 75.degree. F. representative of
room temperatures. The data is as follows:
TABLE I ______________________________________ 25.degree. F.
45.degree. F. 75.degree. F. ______________________________________
1 D. W. 130 147 285 2 M. D. 113 138 300 3 I. D. 138 180 285 4 P. D.
135 135 380 5 Patent Example 1 155 155 235
______________________________________
Such a range of penetration values shows a product consistency
softer than similar products in the market place at the low
temperatures yet firmer than similar products at warmer
temperatures. This phenomenon can be readily seen when the
penetration values are plotted as a curve of penetration against
temperature and compared against such curves for similar products
as seen in the accompanying drawing.
The presence of the solid fat in the beta-prime crystal state has
been shown by X-ray diffraction photography. The diffraction
pattern produced shows defraction lines of 4.20 and 3.80 angstrom
units which supports the conclusion that the fat crystals were
exclusively in the beta-prime crystal form.
EXAMPLE 2
This example illustrates the formation of a hard, low-calorie
spread with a fat content of 40% and suitable for stick or pat form
according to the invention.
Palm kernel oline and palm oil in 75:25 proportion were
hydrogenated at 300.degree. F. using a suspension of 0.2% nickel
catalyst (26% Ni) to an iodine value of less than 2.0 to form
saturated product of melt point 119.degree. F.
The hydrogenated material was filtered to remove the nickel and
steam stripped under vacuum to decrease the fatty acid content
below about 0.03 wt%. Under a high vacuum of 2-3 mm Hg, the mixture
was heated to 250.degree. F. and a 0.05% sodium methoxide catalyst
added with intense agitation for 15 minutes. A sample of product
was analyzed to confirm that interesterification was complete as
determined by a 10.degree. F. lowering of the melt point as
compared to the mixture prior to interesterification. The
temperature of the reaction mixture was decreased to 180.degree. F.
and 0.4 wt.% of a 30% aqueous solution of magnesium sulphate in hot
water was added to destroy residual catalyst. The temperature was
then raised to 210.degree. F. and 1% bleaching earth was added to
bleach the product. Thereafter the interesterified material was
cooled and filtered. The hardstock product was found to have an SFI
solids value of 34% at 92.degree. F. and a Wiley Melt Point of
109.degree. F.
The hardstock described was mixed in a proportion 25:75 with liquid
sunflower oil to form the fat portion of the following formula:
______________________________________ FAT PHASE Oil Blend 39.00
Lecithin 0.20 Monoglycerides 0.50 Vitamins & Color 0.009
AQUEOUS PHASE Water 57.62 Salt 2.00 Whey Powder 0.50 Potassium
Sorbate 0.07 Citric Acid 0.001 Alginate 0.10
______________________________________
The fat phase was added first to the emulsion feed tank, heated to
125.degree. F. and circulated through a Gaulin Hydroshear unit. The
water phase was heated to 125.degree. F. and added to the emulsion
feed tank with circulation continuing through the Gaulin Hydroshear
unit. The emulsion was supercooled through three Votator
scraped-surface chill tubes then to cycled resting tubes emerging
at 46.+-.2.degree. F. in state suitable for forming into pats or
sticks. The resulting stick diet margarine spread readily, did not
exhibit oil or water separation during processing or subsequently
at room temperature and had a good mouth break.
The stick diet margarine had a penetration value of 120 being in
units of 0.1 mm using an ASTM grease cone at 45.degree. F.
In addition, the product had excellent freeze/thaw stability when
cycled for 48 hour periods at 5.degree. F. and 80.degree. F.
The above description is presented for the purpose of enabling the
person skilled in the art to make and use the invention. The
description is not intended to explain each and every obvious
modification and variation of the invention which will become
apparent to the skilled worker upon reading. It is intended,
however, to include all such modifications and variations within
the scope of the invention which is defined by the following
claims.
* * * * *